O,n-diacylated-3,4-dihalophenylhydroxylamines as herbicides



3,219,428 O,N-DEACYLATED-3,4-DIHALOPHENYLHY- DROXYLAMINES AS HERBECIDES Edward ll). Weil, Lewiston, and Jerome Linder, Niagara Falls, N.Y., assignors to Hooker Chemical Corporation,

Niagara Falis, N.Y., a corporation of New York No Drawing. Filed Apr. 17, 1961, Ser. No. 103,253 Claims. (Ci. 712.6)

This invention describes novel organic compositions of matter useful as selective post-emergence herbicides. More particularly, this invention concern a series of selective post-emergence herbicides certain O,N- diacylated-3,4-dihalophenylhyroxylamines which have not been previously described in the literature. The scope of the inventive concept intended to be covered is indicated by the structural formula below:

A B -Q where X is halogen, preferably chlorine, and where A and B, which may be the same or different, are organic radicals selected from the group consisting of the aliphatic acyl radicals having three to six carbon atoms and having at least one methyl group on the carbon atom adjacent to the carbonyl group.

Illustrative compound intended to be within this invention include among others O,N-dipropionyl-3,4- dichlorophenylhydroxylamine, O,N diisobutyryl 3,4 dichlorophenylhydroxylamine, O,N dimethacrylyl 3,4 dichlorophenylhydroxylamine, O,N-di(Z-methylbutyroyl) 3 ,4-dichlorophenylhydroxylamine, O,N-di Z-methylpentanoyl) -3 ,4-dichlorophenylhydroxylamine, O,N-dipropionyl-3,4-dibromophenylhydroxylarnine, O,N-diisobutyryl- 3 ,4-dibromophenylhydroxylamine, O,N-dimethacrylyl- 3 ,4-dibromophenylhydnoxylamine, O,N-di Z-methylbutyroyl)-3,4-dibromophenylhydroxylamine and O,N-di(2- methylpentanoyl) 3,4 dibromophenylhydroxylamine. While all of the above compounds are good herbicides for several reasons including economy, the O,N-dipropionyl, O,N-diisobutyryl and O,N-dimethacrylyl-3,4- dichlorophenylhydroxylamines are especially advantageous and thus are the preferred embodiments of this invention.

One of the herbicidal problems upon which a great deal of time and effort has been unsuccessfully expended i to find, a selective herbicide capable of controlling weeds post-emergence in broad-leaf (dicotyledonous) crops such as cabbage, cotton, soybeans, potatoes, tomatoes, carrots, etc., without harming the crops themselves. Initially, it was hoped that 2,4-dichlorophenoxyacetic acid (2,4-D), a selective herbicide against weeds post-emergence in grassy (monocotyledonous) crops, would prove to be satisfactory, but due to 2,4-Ds relatively high phytotoxicity to broad-leaf crops this has rarely been possible. Even with certain grassy crops such a rice, 2,4-D has been unsatisfactory, since it fails to control the major grassy weeds. Some good results have been obtained using herbicides in oil where herbicide resistant to broadleaf crops such as carrots are involved, but the ordinary broad-leaf crop i too severely damaged, and most farmers have resigned themselves to the safe but more 3,219,428 Patented Nov. 23, 1965 time consuming, tedious and expensive hand weeding and mechanical cultivating.

Thus, the discovery of a novel selective herbicidal series of compounds possessing high phytotoxicity toward weeds after emergence and low phytotoxicity against broad-leaf crops and certain grassy crops olfers the advantage of dispensing with the more expensive laborious hand and machine cultivating and at the same time produces higher yields of the sought crop.

While selectivity and low phytotoxicity toward broadleaf crops is an important attribute possessed by the inventive compositions, there are equally important additional advantages some of which will be disclosed for the sake of illustration.

An additional advantage of the compounds of the invention is that they have sufiicient selectivity when used at the preferred rates, to control Weedy grasse such as crabgrass and barnyard grass post-emergence in the presence of certain desirable grasses such as bluegrass, ryegnass, other turf grasses, as well as rice and sugar cane, without serious damage to these crops.

Yet another advantage of the novel compositions of this invention is that they may be used in grades of purity ranging from the crystalline to a technical crude. Furthermore, these novel herbicidal compositions offer the advantage of compatability with a host of other herbicides such as the metal borates and chlorates, 2,4-D, the herbicidal triazines, the herbicidal ureas, the herbicidal petroleum oils and the like, with fungicides such as the metal dimethyldithiocarbamates and ethylenebis-(dithiocarbamates), with insecticides such as benzene hexachloride and chlordane, with fertilizers such as urea and ammonium nitrate, and various adjuvants and diluent well known to the art. Thus, these herbicides may be used by themselves or made the subject of liquid or solid formulations ranging from the very simple to the more complex. For example, if it is desired these compositions may be made the subject of a liquid formulation by diluting, dispersing, dissolving or emulsifying in a liquid carrier containing a surface active or dispersing or emulsifying adjuvant or a combination of these adjuvants in liquid carriers such as water or organic solvents such as petroleum hydrocarbons, alcohols, ketones, esters, glycol or combinations thereof. Or alternatively, the novel herbicides may be made up as solid formulations of powders, dusts, wettable dusts, granules or pellets using solid diluents such as tales, olays, flours, starches, diatomaceous earths, mica, alkaline earth, carbonates and phosphates either finely divided, granular or pelleted in form.

These solid and liquid formulations facilitate handling and application and sometimes enhance herbicidal activity to more than an additive degree.

The liquid compositions, whether solutions or dispersions of the active agents in a liquid solvent and also the wettable powder or dust compositions of this invention may contain as a conditioning agent one or more surface active agents in amounts sufficient to render the composition readily dispersible in water. By the term surface active agents are included wetting agents, dispersing agents, emulsifying agents and the like. A satisfactory but not complete list of such agents is set forth in an article in Soap and Chemical Specialties, vol. 31, No. 7, pages 50-61; No. 8, pages 4861; No. 9, pages 52-67, and No. 10, pages 38(67) 1955. Other sources of ad- 3 juvant materials are set forth in Bulletin E-607 of the Bureau of Entomology and Plant Quarantine of the United States Department of Agriculture.

While the manner and method of application of the inventive compositions is varied and largely dependent upon the climatic conditions, crop treated, the weeds to be eradicated, the equipment available and the convenience of the user, a preferred embodiment of this invention is to apply these herbicides as a spray after making them up as a liquid formulation comprised of several times their Weight of non-phytotoxic solvents such as xylene with small quantities of emulsifiers such as the commercial polyoxyethylene ethers and the alkylaryl sulfonates. This mixture is emulsified with water and sprayed on the weed population growing amidst the desired crop such as soybeans, cabbage, potatoes, tomatoes, rice, carrots, turf grasses, etc.

The rate of application cannot be precisely stated due to varying degree of resistance possessed by the weed species and crop, the stage of weed and crop growth, the soil type and climatic conditions, but in general, the rates will be at least one-quarter of a pound of herbicide per acre and for reasons of cost, will seldom exceed forty pounds per acre with the preferred range falling within one-half to ten pounds per acre. Where the weeds are in an early stage of growth, and consequently are more susceptible, they will frequently respond to the rates from one-half to four pounds per acre while older weeds or weeds that are to be totally eradicated from ornamental beds or turf may require rates in excess of twenty pounds per acre.

The compounds of this invention may conveniently be prepared by treating 3,4-dichlorophenylhydroxylamine or its salts, which are well known compounds, with at least two moles of the acylating agent. Suitable acylating agents include the propionyl, isobutyryl or methacrylyl halides, anhydrides, or the generally slower reacting esters. While catalysts are not essential to the success of the preparative reaction, where the acylating agent is the halide or the anhydn'de, the presence of an acid acceptor such as a tertiary amine or inorganic base is helpful in speeding up the reaction and insuring that the reaction goes to completeness. Where the salts of 3,4-dichlorophenylhydroxylamine such as the hydrochloride are used instead of the amine it is advantageous to add an additional mole equivalent of a base to liberate the free 3,4-dichlorophenylhydroxylamine.

In order to better illustrate the workings of this invention the following examples are given. These examples illustrate the preparation of some of the inventive compositions, formulations used and the testing procedure used to evaluate the worth of the compositions as herbicides.

EXAMPLE l.PREPARATION OF O,N-DIPROPIO- NYL-3,4-DICHLOROPHENYLHYDROXYLAMINE In an appropriate reaction flask is placed a solution consisting of one mole of 3,4-dichlorophenylhydroxylamine, two moles of triethylamine in six hundred milliliters of dry benzene. The solution is cooled to fifteen degrees centigrade and nitrogen under positive pressure is applied to the reactor. To this solution is added two moles of propionyl chloride at a sufficient rate so that the reaction temperature does not rise above twenty degrees centigrade. The reaction mixture is stirred for an additional two hours and filtered. The filter cake is washed with benzene and discarded. The filtrate is washed with dilute hydrochloric acid, Water, sodium bicarbonate and water, in the order given, then dried. The benzene is evaporated leaving an oil which is dissolved in hexane and the insoluble material removed by filtration. After evaporation of the hexane two hundred and twenty-seven grams of an oil (ninety-four percent yield), is obtained, which boils at one hundred and fifty to one hundred and fifty-five at 0.25 millimeter pressure. Elemental analysis and infra-red analysis establishes the identity of the product as O,N-dipropionyl-3,4-dichlorophenylhydroxylamine in a technical degree of purity.

Analysis.Calcd. fOI' C12H1303NC12 C1, N, 4.83%. Found: CI, 23.9%; N, 4.32%.

EXAMPLE 2.PREPARATION OF O,N-DIISOBU- TYRYL 3,4 DICHLOROPHENYLHYDROXYL- AMINE EXAMPLE 3.PREPARATION OF O,N-DIMETH- ACRYLYL 3,4-DICHLOROPHENYLHYDROXYL- AMINE Using the same procedure and reaction conditions described in Example 1, the above named product is formed in good yield. The product is an oil whose infra-red spectrum and elemental analysis confirmed the presence of the desired O,N-dimethacrylyl.

AnalySis.-Calcd. for C14H1303NC12: Found: Cl, 22.4%; N, 4.5%.

EXAMPLE 4.EVALUATION OF THE COM- POUNDS OF THIS INVENTION AND RELATED STRUCTURES AS HERBICIDES Greenhouse tests of herbicidal activity are performed at an application rate of four pounds of active ingredient per acre as follows. The compound is dissolved in several parts by weight of a substantially non-phytotoxic mixture of xylene, isophorone, and a commercial polyoxyethylenealkylaryl sulfonate emulsifier mixture and the solution emulsified with water and sprayed on a population of seedlings of representative annual weeds, principally ragweed, lambsquarters and button weed, said weeds having emerged one to three weeks prior to the spraying. The ratings of weed kill are given in the last column of the table labeled Her-bicidal activity, and are scaled from 0-10, 0 being no effect and 10 being one hundred percent kill, the intermediate ratings being a visual estimate of percent weed kill. A rating under 7 is considered to be unsatisfactory. The results appear in the table below. Seedling ryegrass under these same test conditions was not seriously injured.

Table 1 Compound: Herbicidal activity rating O,N diisopropionyl 3,4 dichlorophenylhydroxylamine 10 O,N diisobutyryl 3,4 dichloropheny1 hydroxylamine 8-10 O,N dimethylacrylyl 2,4 dichlorophenylhydroxylamine 7-8 O,N di(2 methylpentanoyl) 3,4 dichlorophenylhydroxylamine 7 3,4 dichlorophenylhydroxylamine 0 O,N diacetyl 4 chlorophenylhydroxylamine O2 O,N diacetyl 3,4 dichlorophenylhydroxylamine 0 O,N dioctanoyl 3,4 dichlorophenylhydroxylamine 0 O,N diacrylyl 3,4 dichlorophenylhydroxylamine 0 O,N dipropionyl 3,4 dimethylphenylhydroxylaniine 0 5 EXAMPLE 5.EVALUATION OF THE COM- POUNDS OF THIS INVENTION AS SELECTIVE HERBICIDES Using the same techniques and conditions, concentrations (four pounds per acre), and rating system given in Example 5, the compounds of this invention are tested in an area in which soybeans, cabbages, potatoes and tomatoes are growing. The compounds are rated in two respects, first, as to the weed kill, and the second, as to injury to the foliage of the crop.

Table II Herbicidal Damage to Compound Activity Vegetable Rating Crops 0,N-dipropionyl-3,4-dichlorophenylhy- 10 N o significant droxylamine. damage. O,N-diisobutyryl-3,4-diehlorophenylhy- 8-10 Do.

droxylamine. 0,N-dimethacryly1-3,4-dichlorophenylhy- 7-8 Do.

droxylamine.

We claim:

1. O,N-diacylated-3,4-dihalophenyhydroxylamines of the structure:

where X is halogen, and A and B are selected from the group consisting of alkanoyl and alkenoyl radicals of 3 to 6 carbon atoms having at least one methyl group on the carbon atom adjacent to the carbonyl group.

2. O,N dipropionyl-3,4-dichlorophenylhydroxylamine.

3. O,N diisobutyryl 3,4 dichlorophenylhydroxylamine.

4. O,N-dimethacrylyl 3,4 dichlorophenylhydroxylamine.

5. O,N di(2 methylbutyroyl) 3,4 dichlorophenylhydroxylamine.

6. O,N di(2 methylpentanoyl) 3,4 dichlorophenylhydroxylamine,

6 7. A method for the control of weeds comprising applying a phytotoxic amount of an O,N-diacylated-3,4- dihalophenylhydroxylamines of the structure:

References Cited by the Examiner UNITED STATES PATENTS 2,628,253 2/ 1953 .Dowdall 260545 2,671,109 3/1954 Hartley et al 260545 2,863,752 12/1958 Hamm et al. 71-2.3 2,864,679 12/19-58 Hamm et a1. 71-23 2,946,776 7/1960 Scott et a1 260545 X 3,037,058 5/1962 Bluestone et a1 260578 FOREIGN PATENTS 2,315 5/1962 Japan.

OTHER REFERENCES Bamberger: Deutche Chem. Ber, v01. 51, pp. 636- 640 (1918).

LORRAINE A. WEINBERGER, Primary Examiner.

CHARLES B. PARKER, LEON ZITVER, Examiners,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,219,428 November 23, 1965 Edward D. Weil et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 28, for "O,Ndimethacry1yl" read O,N-

dimethyacrylyl-S,4-dichlorophenylhydroxylamine line 61, for "-2,4" read 3,4 column 5, line 24, for "dihalophenyhydroxylamines" read dihalophenylhydroxylamines Signed and sealed this 7th day of February 1967.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Commissioner of Patents Attesting Officer 

1. O,N-DIACYLATED-3,4-DIHALOPHENYHYDROXYLAMINES OF THE STRUCTURE:
 7. A METHOD FOR THE CONTROL OF WEEDS COMPRISING APPLYING A PHYTOTOXIC AMOUNT OF AN 0,N-DIACYLATED-3,4DIHALOPHENYLHYDROXYLAMINES OF THE STRUCTURE: 